1855.] 391 



the rectum ; their openings externally are indicated by a bluish spot on each 

 side of, and distant from, the anus. 



ANNELIDA. 



31. Tecturella ltjctator. Subquadrilateral, turrited above, of the same 

 thickness throughout except toward the posterior extremity ; the rings usually 

 indicated by transverse folds of the envelope which is loose and flabby when the 

 animal is alive, agglutinating sand, and of a yellowish-green color. Rings 

 about forty in number. Anterior tentacles capable of being protruded to con- 

 siderable length, when they are smooth and cylindrical. Posterior tentacles 

 dark green, slender, and very numerous, in two clusters. Superior setae capil- 

 lary, as long as the inferior ones, and eight in number in each of the compressed 

 fascicles which contain them. Inferior pinnae containing each a single long 

 stout hooked seta. Length, 1.5 inch. Found loosely attached under atones 

 near low-water mark. 



Hab. Cape of Good Hope, at Simon's Bay. 



32. Siphonostomum l/Eve. Body thickest near the middle, suddenly tapering 

 and slender posteriorly ; much smoother than is usual in the genus, showing 

 only the delicate, close, slightly-raised annulations. Superior setae capillary ; 

 inferior ones short, strong, curved, but not hooked. Setas of three segments di- 

 rected forward ; those of the first in four fan-like clusters, arranged so as to 

 form a circle around the mouth ; those of the second segment much fewer in 

 number, and placed on the sides of the body only; those of the third rot con- 

 spicuous. Anterior tentacles long, diverging ; posterior ones shorter, slender, 

 about twenty in number, arranged in a half*circle as in Sabella. Colors : body 

 pale reddish ; tentacles zonate with white, brownish, and pale green. Length, 

 2 inches ; breadth, 0.2 inch. Found in holes which it forms in fragments of 

 corals, in the coralline zone. 



Hab. Cape of Good Hope, at False Bay. 



33. Chjetopterus capensis. Small, short, having a general resemblance to 

 C. pergamentaceus ; inhabiting a papyraceus tube. Annulations about thirty in 

 number. Cephalic ring equalling in size the succeeding or first ring. In the 

 first eight rings, the superior pinnae only are developed, and are provided with 

 long lanceolated setae ; those of the third pair, however, have a fasciculus of 

 stout black truncated setae at their bases. Inferior pinnae first appearing on the 

 ninth riug, and provided with short uncinate setas, which have each six or eight 

 uncinas, occupying the whole length of their edges. Dorsal pinnas of the tenth 

 ring expanded into wing-like lobes ; ventral pinna* united into a transverse disc, 

 as is also the case on the 11th, 12th and 13tb. In the lltb 15th rings the dor- 

 sal pinnas are united to form sacs, of which those of the 14th and 15th are much 

 the smallest, and compressed above ; the ventral shields of these two rings are 

 compressed, bilobate, and protruded so as to lose the disc-like form. Dorsal 

 pinnas of the 16th and succeeding rings large and finger-shaped, with capillary 

 setae ; posteriorly they grow more slender but not much shorter. In these 

 ring3 the ventral pinnas form four lobes. Length 2 inches. Found in the cir- 

 cumlittoral zone. 



Hab. Cape of Good Hope, at Simon's Bay. 



34. Chcetopterus luteus. Long and slender, cylindrical, of nearly the same 

 thickness throughout; color lemon-yellow. Tube thin, membranous within, 

 exteriorly composed of mud. Rings about forty in number. Ventral shields of 

 the 14th and 15th rings disk-like as in the others; those of the posterior rings 

 with the two middle lobes only developed. Dorsal pinna? of the posterior rings 

 full and lobe-like at the base, but suddenly tapering into a long sheath for their 

 few capillary setae. Length three inches. Found abundantly on muddy bot- 

 toms in the circumlittoral zone. 



Hab. Australia, at Port Jackson. 



35. Cirratulus al'Stralis. Large, rounded above, and flattened below, pos- 



